The proposed research will compare the prevalence of various psychiatric disorders among the relatives of patients with agoraphobia and with panic disorder. For purposes of this comparison all available first-degree relatives of a group of approximately 20 agoraphobic and 20 panic disorder patients that have been matched for age and sex will be personally interviewed by a research assistant according to a structured format. DSM-III diagnoses will then be established by two psychiatrists through independent and blind review of data from interviews. Where relatives are unavailable for interviews, information from remaining relatives will be pooled for diagnostic purposes. Because the size of the sample for this project is limited the results will be preliminary in nature. They should, however, further the comparison of psychiatric illness patterns among agoraphobic and panic disorder relatives and lead, eventually, to a determination of whether these are separate illnesses or a single disorder.